48 SWINE PLAGUE 



animal. On account of its frequent association with hog 

 cholera, it has been thought b3' some investigators, more 

 especially Billings, Welch and Clements, to be a secondary 

 affection only. In 1895, the writer investigated several out- 

 breaks of this disease in Southern Minnesota where it occurred 

 uncomplicated with hog cholera. More receutl)- two epi- 

 zootics of swine plague have been studied in New York State, 

 where no evidence was found of its being a secondary infection 

 but where in every particular its independent nature was 

 indicated. 



>; 45. Geographical distribution. Swine plague is a 

 wide spread disease in this country. It seems to occur more 

 or less frequently in every state in the Union. It is quite 

 widel}' distributed in Germany, but to what extent it exists in 

 other countries there is little or no availaljle evidence. 



i< 46. Etiology. Swine plague is caused by a non-motile 



elongated, oval bacterium described by Smith in 1886. It is 



identical with the bacillus of Sdiwcinescuchc 



Q *-*y described bv Loeffler in i88s. Hueppe pro- 



nv»Q ft ^P posed the name Bacterium (Bacillus) septi- 



0^ n fl cacmiac hcmorrhagicae for this organism. 



"-i^Q <^ The bacterium of swine plague and its 



g o^ varieties have not been systematically stud- 



ied and classified. It is of interest to note, 



Fig. 5. Baden- however, that the bacteria of rabbit septi- 



uui of swan- plague. • r 1 1 1 1 •, 1 , 



caemia, fowl cholera and wildseuche are 



thought to be identical with it. 



The pathogenic organism associated with the lesions in 

 certain forms of broncho-pneumonia in cattle differs very 

 slightly from this. In human pathology, we find a striking re- 

 semblance in Micrococcus lanceolatus to the swine-plague bac- 

 terium, especially in its manifold and varied pathogenic possi- 

 bilities and its existence in human saliva. 



In grouping these bacteria, the fact should be recognized 

 that experimentally they are not interchangeable in their 

 pathogenesis except for the rabbit. Thus an epizootic form 

 of fowl cholera has not been produced with the swine plague 

 or rabbit septicaemia organism. Further, it has been shown 



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